See-through, augmented-reality head-wearable devices (HWDs) based on free-space projection optics require a combiner lens (e.g., glass) to redirect projected light beams toward the eye of the user. The proper usage of HWDs therefore requires that the combiner lens is, in fact, inserted into the frame. In some examples, the lens may be broken and may have fallen out. In other examples, the lens may be swappable (e.g., multiple lenses may have multiple dimming shades for use in indoor and outdoor environments) and is currently out of the frame. In such examples, there is no surface to redirect the light beams projected by the projector and, therefore, the light beams are cast through an opening in which the lenses were once disposed.
The figures are not to scale. Instead, the thickness of the layers or regions may be enlarged in the drawings. In general, the same reference numbers will be used throughout the drawing(s) and accompanying written description to refer to the same or like parts. As used in this patent, stating that any part (e.g., a layer, film, area, region, or plate) is in any way positioned on (e.g., positioned on, located on, disposed on, or formed on, etc.) another part, indicates that the referenced part is either in contact with the other part, or that the referenced part is above the other part with one or more intermediate part(s) located therebetween. Stating that any part is in contact with another part means that there is no intermediate part between the two parts.